Question

Caroline resting heart is 52 beats per minute (bpm). When she starts running her heart rate increases 1.25% each second until it reaches maximum heart rate of 175 bpm. Find her approximate heart rare after 30 seconds

Answer 1

Answer:74.55 beat per minute

Step-by-step explanation:

Given

Heart beat is 52 beat per minute

i.e. $B=\frac{52}{60}$ beat per sec

If heart rate is increases 1.25 % each sec

suppose B is the heart beat at first second therefore heat beat at 2 nd second

$B_2=B+1.25 \% B$

$B_2=B(1+1.25 \% )$

For 3 rd sec

$B_3=B(1+1.25\%)+1.25\%B(1+1.25\%)$

$B_3=B(1+1.25\%)^2$

similarly for 3 sec

$B_{30}=B(1+1.25\%)^{29}$

$B_{30}=1.433B$

$B_{30}=1.242\ \text{beat per second }$

$B_{30}=74.55\ \text{beat per minute}$